Insecticidal [1-cyano-2-(1h)-isoquino-linyl]-o, o-dialkyl amide esters of phosphothioic acid



United States Patent 3,318,768 INSECTICIDAL 1 (:YANo 2 (1H) ISOQUINO- LINYL] 0,0 DIALKYL AMIDE ESTERS oF PHOSPHOTHIOIC ACID Richard William Young, Wellesley Hills, Mass., and

Ernestine Gelhlum Abraham, Cumberland, Md., assignors to American Cyanamid Company, Stamford, Conn, a corporation of Maine No Drawing. Original application Aug. 14, 1963, Ser. No. 301,946, now Patent No. 3,249,614, dated May 3, 1966. Divided and this application Nov. 4, 1965, Ser. No. 506,412

5 Claims. (Cl. 16733) ON H wherein R is an alkyl substituent from one to four carbon atoms and may be the same or diiferent. Cornpounds within the contemplation of the invention include: [1 cyano 2-(1H)-isoquinolinyl]-0,0-dimethyl amide ester of phosph-orothioic acid; [1-cyano-2-(1H)-isoquinolinyl]-0,0-diethyl amide ester of phosphorothioic acid; [1 cyano 2-(1H)-isoquinolinyl]-0,0-di-n-propy1 amide ester of phosphorothioic acid; [1-cyano-2-(lH)-isoquino 1inyl]-0,0-di-isopropyl amide ester of phosphorothioic acid; [1 cy-ano 2 (1H)-isoquin-olinyl]-0,0-di-n-butyl amide ester of phosphorothioic acid; and [l-cyano-Z- (1H) isoquinolinyl] 0,0 di-iso-butyl amide ester of phosphorothioic acid.

The novel class of compounds as defined hereinabove can be prepared in a straightforward manner by reacting isoquinoline with an alkali metal cyanide and a di(lower) alkyl thiophosphoryl halide. The reaction may be con veniently written as follows:

SOR

S OR

NP MeX 3,318,768 Patented May 9, 1967 In general, it as been found that (a) from 0.5 mol to 2 mols of. isoquinoline, (b) from 2 to 4 mols of an alkali metal cyanide and (c) from -1.5 to 2.5 mols of a dialkylthiophosphoryl halide can be admixed in a suitable inert solvent such as, for instance, methylene chlo ride, chloroform or ether. However, as a preferred op erating range of reactants, 1 mol of the isoquinoline, 2 mols of the dialkylthiophosphoryl halide and 3 mols of the alkali metal cyanide is employed.

The preparation of the novel compositions can be carried out over a wide range of temperatures, usually from about minus 15 C. to about plus 35 C. Since the reaction is exothermic, it is a good operating procedure to maintain a temperature of reaction at be low the boiling point of the solvent employed. After completion of the reaction, the temperature is permitted to rise to room temperature so that recovery of product can be readily had.

In order to more fully describe the present invention, the following representative examples are presented which are not to be taken as limitative but merely as illustrative of the invention. Unless otherwise noted, all parts are by weight.

EXAMPLE 1 Preparation of [1 -cyan0-2- 1H) -is0quin0linyl] -0,0- diethylamide ester of phosphorothz'oic acid To a suitable reaction vessel is added. a mixture of 6 parts of freshly distilled isoquinoline dissolved in 60 parts by volume of methylene chloride and 9.3 parts of potassium cyanide dissolved in 24 parts of water.

The contents of the reaction vessel are stirred and, while stirring, 17.6 parts of diethylthiophosphoryl chloride are added dropwise to the stirred mixture. Reaction is exothermic and the addition of the diethylthiophosphoryl chloride is carried out at such .a rate as to maintain the temperature of the mixture at between about 29 C. and 32 C. The reaction mixture is allowed to stand at room temperature for approximately twelve hours. After completion of reaction, the organic layer is separated and washed with water, followed by sodium bicarbonate-Water wash. Resultant solution is next dried over anhydrous magnesium sulfate and then stripped of solvent at room temperature and at 0.5 mm. Hg pressure.

The semi-solid residue recovered is sucked dry on a Buchner funnel and recrystallized from methanol by pouring the solvent over the product, filtering and chilling the solution in Dry Ice. Eight (8) parts of white solid product melting at 68 C. to 69 C., are obtained.

Upon analysis, the following is recorded in percent:

Calculated: C, 54.51; H. 5.56; N, 9.08; P, 10.04. Found: C, 54.58; H, 5.37; N, 9.24; P, 9.90.

Similarly, the dialkyl amide esters of the above compound, such as the dimethyl, the dipropyl and the dibutyl esters are obtained by substituting for the diethylthio phosphoryl chloride reactant, dimethylthiophosphoryl chloride, dipropylthiophosphoryl chloride and dibutylthiophosphoryl bromide, respectively, in the above example. Each of the corresponding alkyl esters is obtained in good yield.

EXAMPLE 2 3 4 sprayed on army Worms and mites. The results of these 2. An insecticidal composition according to claim 1 tests are tabulated below: wherein the compound is [l cyano-2-(1H)-isoquino- TABLE I linyl]-0,0-diethylamide ester of phosphorothioic acid.

I 3. An insecticidal composition according to claim 1 Percent K111 Concentration 5 Specie wherein the inert solvent comprises a water-acetone sol- 1% 0 vent mixture.

4. A method for controlling insect population which igg 8 comprises: applying to a locus inhabited by insects the MiteS' eggs 109 10 insecticidal composition as defined in claim 1 above.

5. A method according to claim 4 for controlling insect population which comprises: applying to a locus inhabited by insects the insecticidal composition as de- What is claimed is: 1. An insecticidal composition comprising an inert solvent therefor and an effective amount of the compound 15 represented by the formula: fined in claim 2 above.

s on No references cited. II 20 LEWIS GOTTS, Primary Examiner.

OR ON H SHEP K. ROSE, Assistant Examiner.

wherein R is lower alkyl substituent. 

1. AN INSECTICIDAL COMPOSTION COMPRISING AN INERT SOLVENT THERFOR AND AND AN EFFECTIVE AMOUNT OF THE COMPOUND REPRESENT BY THE FORMULA: 